Friction - wear modeling in drilling process of H-13 tool steel

Abstract

Simulation of metal cutting is complex both from numerical and physical perspective. The scope of this work is to elaborate on the process and physics of metal cutting, and more specifically drilling. The description of H-13 steel dry drilling with the use of a single-layer TiN coated carbide twist drill is presented. H-13 is a high strength alloy steel used in demanding applications and elevated temperatures. A simulation model was developed with use of Deform-3D software, and an experiment was conducted in order to evaluate the acquired simulation results, meaning the wear mechanisms and thermal loads implemented during the process of drilling. The Usui wear model was used for the calculation of the wear rate of the drill. Regarding the experiment, a thermal camera was used in order to record the temperature of the drill after the process. The comparative analysis of the simulation models and the experiment showed that adhesion is the dominant wear mechanism. Higher wear values were observed in the rake faces of the drill, where the coating starts to fade, due to built-up edges (BUE). The tool and workpiece temperatures reach near steady state conditions during process. Elevated temperatures are applied on the removed material. Good chip evacuation and chip length indicate that coated drills with optimized geometry are suitable for drilling tough materials.